The following invention relates to a squeegee attachment for a vacuum cleaner of the wet/dry variety for removing dirt and foreign matter from planar surfaces such as windows.
Squeegee blades are implements for use in window washing or the cleaning of planar surfaces. A squeegee blade is a thin, deformable blade usually made of rubber, which is held in an elongate holder and drawn across the window by a handle connected at an oblique angle to the holder. The handle can either be grasped by the hand or fitted with extension rods for reaching high windows. Usually in cleaning large windows a cleaning fluid is first applied to the surface of the glass with an applicator such as a sponge. The squeegee blade then is drawn across the surface of the glass removing the cleaning fluid along with the dirt. While this method is useful for cleaning most of the surface of the glass, a problem exists near the bottom of the glass where all the dirt and cleaning fluid collects because there is no collection point or place for the fluid to flow from which it can be easily removed. The fluid and dirt simply collect at the bottom of the glass in the windowsill, and there is no effective means of removing it from this location.
In the past, rug and floor cleaners have included cleaning attachments for a wet/dry vacuum cleaner which included brushes and/or blades to loosen the dirt. An example of such a device is shown in Thompson U.S. Pat. No. 2,893,046. The Thompson patent discloses a cleaning attachment having a pivotallymounted blade which moves back and forth within a suction channel in the head of the cleaning device for dislodging dirt or other foreign matter. Several problems are inherent in the structure of the Thompson device. First, the mounting of the squeegee blade in the handle does not provide for the most efficient removal of water and/or cleaning fluid. Second, the blade extends too far forwardly of the head for creating efficient suction at the juncture of the blade and the floor where the water collects, and third, the blade is mounted so as to pivot back and forth within the vacuum channel. This mounting does not provide for enough suction either on the push or the pull stroke because in neither stroke is the suction channel close enough to the place where the water collects to provide efficient suction.
A similar design is shown in Kirby U.S. Pat. No. 1,982,345. The device of the Kirby patent includes a squeegee centrally mounted within an elongate suction chamber in the forward end of the cleaning attachment. As in the Thompson device, the squeegee in the Kirby patent is intended to be operative both on the pull and on the push stroke but, as mentioned above, the reciprocating blade action results in too little suction for efficient collecting of the water. The Kirby device also has a brush sandwiched between two squeegee blades that projects forwardly of the blades thus hindering any suction-type seal that could be made between the blade, the glass and the intake or suction port.
The reason for this inability to create efficient suction in a device having a pivoting blade which is intended to remove fluid on both the forward and reverse stroke, is that the effective area of the suction port is too large. The maximum amount of suction will occur in a region near the point of contact between the blade and the glass or planar surface to be cleaned. Efficient suction will not occur, however, if the exterior walls of the attachment forming the suction channel are spread too broadly over and too far away from this point of contact.
Another problem that occurs in both of the aforementioned devices, and also described in Congdon U.S. Pat. No. 3,079,623, is that the blade and the suction channel are oriented perpendicular to the surface to be cleaned. Especially on the downstroke, the fluid must be drawn off the glass at right angles to the normal direction of flow which would be downward due to the force of gravity. Thus a good deal of the fluid escapes and is not drawn up into the vacuum channel. Such an orientation is necessary, however, if one wishes to provide for the ability of the device to clean both on the upstroke and on the downstroke. While theoretically such a device might appear to be more efficient, it is in reality inefficient and leads to smearing of the cleaning fluid or water across the window.